Bond market vigilantes Why yields are rising as governments count the costs

They punish governments that dare to deviate from financial orthodoxy. 

- Larry Elliott

They strike fear into the hearts of finance ministers. They were seemingly a dying breed in the years between the crash of the late 2000s and the 2020 Covid-19 pandemic, but now the bond market vigilantes are heading back into town.

There was a time, not so long ago, when governments were able to borrow as much as they wanted at rock-bottom rates. For almost three years, investors paid for the privilege of lending the German government money because bond yields were below zero.

Those days are over. It now costs the German government almost 3% to attract buyers for its 10-year bonds. In the US, the interest rate or yield - on a 10-year bond briefly rose above 5% this week to its highest level since 2007. The yield on 30-year UK government debt hit levels not seen since the late 1990s.

Unusually, the rise in bond yields has come at a time of heightened international tension. Wars make investors nervous, and when conflicts start there tends to be a flight out of shares and into the haven represented by bonds. US treasury bonds are considered one of the safer havens, because the dollar has the lucrative privilege of being the world's reserve currency.

This time it has been different. While there was a brief decline after the start of the war between Israel and Hamas this month, US bond yields quickly resumed their upward trend.